Unit 5: Evolutionary Patterns, Phylogeny, and Macroevolution Flashcards
Why do we use phylogenetic trees?
This is a branching diagram that shows the relationships between species often according to the time since a common ancestor.
What is phylogeny?
History of descent with branching.
What is the order of the phylogeny?
- ) Individuals
- ) Population
- ) Species
- ) Phylogeny
What is the phylogram?
This is a diagram where the branch length determines the amount of inferred evolutionary time.
What is the cladogram?
This is when the branches are of equal length.
What is the difference between phylograms and cladograms?
The length of the branches and the use of time in phylograms.
What are sister groups?
Groups that share a common ancestor that is uncommon to other groups.
What is a clade?
A section of the diagram that includes the sister groups and common ancestors.
What is a monophyletic group?
These include common ancestors and all of its descendants.
What is a paraphyletic group?
These include common ancestors and some but not all of its descendants.
What is a polyphyletic group?
Does not include the common ancestors.
What are the characters that are used in a phylogeny?
The character used vary among but not within species and have a genetic basis.
What are homologous characters?
These are shared because of common ancestry and derived characters as a result.
What are analogous characters?
Homoplasy means similar in appearance but not in origin shared because of converging evolution.
What is homology?
Evolved once in the common ancestor.
What is homoplasy?
Evolved independently.
How are homologies recognized?
- Structural similarities
- Relations between parts
- Embryonic development
What is macroevolution?
The evolution above the species level such as the assessment of diversity of an entire clade and its position on the tree.
What is adaptive radiation?
The rapid evolution of new species occupying new niches.
What is anagenesis?
Speciation wherein the ancestors species is wholly replaced by new species.
What is cladogenesis?
Parent species splits into 2 species.
What is graduated evolution?
Slow and steady gradual evolutions.
What is punctuated evolution?
Rate and rapid on a geological time scale events of branching speciation which results in cladogenesis.
What is taxonomy?
This is the categorization of organisms into different groups.
Where were the first prokaryotes found?
Through sediment layers called stromatolites.
What was the Proterozoic period?
This was the archaea period of 4 billion to 510 million years ago.
How did the oxygenation event occur?
The oxygenation event was a result of photosynthesis which increased the oxygen levels.
How did the first eukaryote come about?
Through the process of endosymbiosis the first eukaryotic organism came about.
What was the Palaeozoic period?
The Cambrian explosion; invasion of land; appearance of gymnosperms; major of tetrapods.
What was the Cambrian explosion?
This was the rapid appearance of many groups of organisms about 530 MYA.
What was the Ediacaran Faun?
This was the period 640 MYA with lots of weird forms of animals that are now extinct.
